It is generally desired in the operation of vehicles to hold the vehicles from movement after the operator has applied the brakes and caused the vehicle to be brought to a stop, and before the operator has resumed operation of the vehicle. With most vehicles, however, after stopping the vehicle by applying the brakes using the brake pedal, the brakes are released when the pedal is released and it is necessary to use a parking brake if the vehicle is stopped on a sloping road or the like. However, the use of a parking brake is troublesome. Therefore, the parking brake is often not used except on a sloping road. Frequently, vehicles when stopped are thus left without the brakes being applied which involves the possibility of an unexpected movement of the vehicle from its stopped position. Furthermore, in the operation of a vehicle with manual transmission, for example, when a vehicle is stopped at a traffic light on an upwardly sloping road, it is difficult to hold the vehicle from moving backward when the light changes and the operator must remove the right foot from the brake pedal and press it on the accelerator, since the release of the brakes when the foot is removed from the brake pedal will allow the vehicle to roll backward unless the clutch is smoothly engaged to cause the vehicle to move forward under power.